Influenza virus causes serious respiratory illness and has potential to cause pandemics. Due to the high mutation rate in influenza genes, antigenic drift creates a new strain each year. Consequently there is significant economic burden to monitor virus activity and to create and distribute new influenza vaccines to the public each year. On the surface of the influenza A virion is found a highly conserved membrane protein (M2) which lends itself as a potential target for developing a universal influenza vaccine. However, under natural circumstances, M2 is present in very small numbers (16-22 per virus particles), is not well exposed at the virus surface and is poorly immunogenic. Our approach to overcome these challenges is to emulate virus structure through the use of a synthetic gold (Au) nanoparticle (AuNP) conjugated with different functional peptides creating a nanoengineered virus-mimic (NVM). The NVM can carry an antigen of choice in high density. In addition, other functional peptides can also be easily attached to the NVM. For example, peptides that can enable NVMs to enter cells or to activate the immune cells of the body could be attached. Based on the NVM concept, we propose to develop a universal influenza A vaccine delivery system. As the influenza antigen we have selected the highly conserved extracellular portion of the influenza-A matrix protein M2 (M2e), and as the cell-penetrating peptide to enhance entry of NVMs into cells we have selected tat (47-58) peptide derived from the human immunodeficiency virus (HIV-1). Our hypothesis is that NVMs presenting a high density of M2e on their surface with tat as a helper peptide can stimulate a broadly protective anti-influenza A immune response. The objectives of this study are to optimize NVMs as an influenza vaccine system and to evaluate their protective efficacy in mice animal models using live infectious challenges with heterologous and heterosubtypic influenza strains. Importantly we will evaluate systemic and mucosal B cell immunity for the intranasal routes of immunization. This project is novel because it seeks to exploit nanotechnology to create a modular vaccine delivery system, which like 'lego' pieces, can be used to assemble NVMs with unique functionalities. This concept can be used broadly used to create vaccine delivery systems against a host of infectious diseases.